Method of applying particles to an electrofoam during electroplating



Nov. 10, 1964 H. CHESSIN ETAL 3,156,632

METHOD OF APPLYING PARTICLES TO AN ELECTROFOAM DURING ELECTROPLATINGFiled Feb. 11. 1960 JIGLZ PLA TING CURREN T NODES 24- SLIDE? 3/INVENTORS. HYMAN CHESS/N an d l qcpuEs J. J L H/L HORST A TT'ORNEYS.

United States Patent METHQD 0F APPLYING PARTICLES TO AN ELEC- TROFGAMDURENG ELECTROPLATENG Hyman Chessin, Gleam, N.Y., and Jacques J. J. L.Hilhorst, Eldred, PSI-9 assignors to Van Der Horst Corporation ofAmerica, Olean, N.Y.

Filed Feb. 11, 1960, Ser. No. 8,074 7 Claims. (Cl. 204-16) Thisinvention relates to improved electroforms and method for producing thesame; said electroforms being of composite nature comprisingelectroplated matrix material embodying other particulate materialinclusions therein.

It has been long considered desirable to be able to produce electroformshaving specified properties such as inherent lubricity, or high wearresistance, or the like; such as for example in the case of piston ringsor other bearing surfaces. in other cases it is required to provideinherent abrasiveness, such as for example in the case of abrasive rollsor discs or other abrasive stmctures; in any case the prime objectivebeing to give the finished product the basic properties of the matrixmetal, such as strength or lightness or cheapness, in addition to thesurface properties desired for the composite material.

Previously employed methods utilized for such purposes include theconventional metal spraying, electrophoresis, and hot pressingtechniques, but have resulted in only limited success. Spraying ofmetals or of metals composite with other materials has proven to beunsuitable for such purposes because the coherence and adherence of thecomponents of the sprayed deposits are insufficient to withstand severemechanical and thermal stresses. The same is true of the resultsobtained by the hot press-coating technique. Electrophoresis techniquesrequire extremely high temperature treatment, usually in a reducingatmosphere, to make the deposit adherent and coherent. Hence suchprocesses are relatively costly and tend to cause .warpage deformationsand/or other damage to the basis material. For example, use of thistechnique would tend to anneal or remove temper from a previouslyheat-treated piston ring blank.

Electrodeposition techniques have been previously utilized to formcomposite coatings, and have the advantages of forming coherent andadherent coatings without the necessity for use of high temperaturereduction processes, or the like. Particulate materials have beencoincidentally incorporated in electrodeposit, for example by suspendingthe particles in the plating solution. However, such techniques are ofonly limited commercial feasibility because it is difiicult to maintainparticles in suspension in a plating bath, and because constant orfrequent filtration of a plating bath is necessary to. obtain depositionof good quality electroplates. It is obvious that filtration of aplating bath to which suspension materials have been added will defeatthe purpose of the additive. Furthermore, coatings produced by suchmethods have been found to be inherently highly porous.

For example, colloidal graphite has been suspended in copper, nickel andzinc plating baths to form composite coatings of varying porosities.Whereas porosity of substantial degree may be tolerated or evendesirable in some cases, it is obvious that the higher the percentage ofvoids in the coating, the weaker will be its tensile and shearstrengths. Furthermore, the suspended par ticles used in connection withsuch techniques must be chemically inert so far as the plating bath isconcerned. This definitely limits the choice of materials which may beincorporated in the composite electroplate coating by any suchsuspension" techniques.

3,156,632 Patented Nov. 10, 1964 The present invention provides asuperior method whereby any material chosen for its desirable propertiesmay be incorporated in an electrodeposit to form a composite body orcoating of superior physical properties. Generally stated, the methodinvolves moving the surface which is being plated in pressure-bearingrelation against a solid mass which contains the material to beincorporated within the plate, so as to cause attrition of the mass andprogressive wiping of particles of the material of the mass into theplate being formed. These particles are thus bound to the dynamicsurface by the plating metal and become intimately incorporated withinthe plate as it continues to grow.

The mass material may for example be in the form of a solid metal, suchas lead or silver, which will wear away by the relative motion of themass and the plating surface. However, the mass may comprise anagglomeration of particulate matter of powder or fibre forms forexample, suitably bound or compacted into a solid mass. Materialssuitable for inclusion as lubricity agents for example are lead, tin,molybdenum disulfide, and graphite. Materials suitable for inclusion asabrasive agents for example, are silica, silicon and tungsten carbides,alumina, molybdenum disilicate, and diamond dust or grit. Thesematerials may be incorporated in a solid slider mass by compaction, withor without heat, and with or without a suitable binder material.Suitable binder materials include for example glues or syntheticplastics such as the thermoplastic methacrylates which can be mixed withthe particulate matter in powdered form; the resultant mixture beingthen compacted into solid form by the application of moderate heat andpressure. Thermosetting plastics may be similarly used. Also, it hasbeen found convenient to use the catalyst-setting plastics, such as theepoxies, since the particulate matters are readily mixed with suchplastics in simple molds of convenient size and shape to solidify. It isa feature of the present invention that the composites so formed maycomprise resulting coating consisted of a composite of molybdenumdisulfide and tin particles distributed throughout an electrodepositediron matrix. Analysis showed that the electrolytic iron plated with theslider in contact contained 0.205% of carbon, 0.12% tin and 0.09%molybdenum (or 0.15% molybdenum disulfide); identical electrolytic irondeposited without the slider in contact with the plating surfacecontained 0.048% carbon, 0.011% tin and 0.007% molybdenum. The wear andnonscuffing, non-galling compatibility of the slider-treated coating issuperior because of the self-lubricating properties of the coating, thisself lubricity being endowed by the particles distributed throughout thecoating.

Another example of the use of this method includes the forming of anabrasive disc by rotating the disc as the cathode in a nickel platingsolution and pressing thereon a solid slide-r consisting of by Weightalumina and 20% by Weight methyl methacrylate. As a result the coatingwill consist of a composite of abrasive alumina particles embeddedthroughout a nickel matrix.

Anotherexample to illustrate the range of properties which may beobtained is the coating of shafts by plating in a nickel bath while theshaft is rotating against a slider consisting of 80% by weight tungstencarbide and 20% by weight of Bakelite. The resulting composite coatingwill have excellent wear and scuff-resistance.

Types of mechanisms which may be used in carrying out the invention areillustrated in the accompanying drawing wherein:

FIG. 1 is a partially schematic vertical sectional View through aplating tank and apparatus for practicing the method of invention inconjunction with cylindrically surfaced workpieces, uch as a gang ofpiston ring blanks;

FIG. 2 is an enlarged scale sectional view taken on line Illl of FIG. 1;

FIG. 3 is a fragmentary view of another form of apparatus for practicingthe method of the present invention in connection with flat or curvedworkpieces;

FIGS. 4, 5 are schematic illustrations of still other forms ofapparatuses for practicing the invention on various kinds of workpieces;and

FIG. 6 is a fragmentary sectional view, on greatly enlarged scale,illustrating the nature of a composite coating product of the method ofthe invention as applied to a curved surface workpiece.

As shown for example in FIG. 1 of the drawing herewith, the apparatusthereof is arranged to surface-coat gangs of ring-shaped workpieces,such as engine piston rings, to furnish the latter with wearing surfacesof improved lubricity and wear resistant characteristics. In this case amandrel as indicated at lit is arranged to mount therearound a pluralityof piston ring blanks 12 in side-by-side stacked relation; the mandrelIt) being journalled as indicated at 14 upon hangers 15, therebysuspending the mandrel within a plating tank 13. A motor 2% and suitablechain and sprocket drive means or the like as indicated at 22 isprovided to cause rotation of the mandrel.

Anodes comprising bars or plates of the matrix metal or material to beplated on the workpieces as indicated at 24 are disposed alongside themandrel and ring assembly, and are connected as through a commonconductor 23 to the plating current supply. Another conductor 29connects to the brackets 15, 16 carrying the mandrel ill, thereby makingthe workpieces 12 the cathode elements of the plating system. Thus itwill be appreciated that upon supplying of a suitable plating solutionin the tank 18 and application of plating current to the conductors 28,29, an electroplating process will be established to plate the matrixmaterial of the anodes on the workpieces in accord with the well knownprinciples of the plating art.

In accord with the present invention however, a second supply ofmaterial is to be embodied in the matrix material of the compositecoating to be applied to the workpieces. In the case of FIG. 1 thismaterial source is provided in the form of a block 31 of particulatematerial or materials, the particles of which are to be incorporatedwithin the material being plated as the process advances. In accord withthe invention the block 31, comprising a compaction or otherwisebonded-together agglomeration of particulates, is mounted inslide-bearing relation against the periphery of the gang of workpieces12 as they rotate; the block mounting arrangement being shown to includea spring device 32 arranged to permit the block 31 to move relative tothe mandrel and workpieces in response to building up of theelectroplate as the electroform operation progresses. Thus it will beappreciated that as the plating of material on the surfaces of the rings12 progresses, particles 34 from the block 31 are simultaneously beingworked into the electroform (FIG. 6).

FIGS. 3, 4, 5, illustrate other specific examples of mechanisms forpracticing the method of the invention in connection with variouslyshaped workpieces. For example, in FIG. 3, the workpiece in the form ofa fiat plate as indicated at 4% may be held in a jig 42 while submergedin an electroplating tank, while the source of particulate material tobe embodied in the electroform may be supplied in block form asindicated at 44 and mounted upon a a shaft 46 journalled in a bearing 43which is mounted for reciprocation in directions normal to the workpieceby means of a slide bearing block 49. A compression spring 5b isprovided to furnish the preferred degree of pressure between the block4-.- and the workpiece 4d; the spring tension being adjustable by meansof a screw device 52. To distribute the particulate inclusion treatmentover the expanse of the workpiece 49 the shaft 46 may be arranged forvertical reciprocation in the bearing 48, as by means of the pulley andconnecting rod arrangement indicated at 53, 54. Similarly, horizontalrelative movements between the workpiece and the wheel 44 may beprovided for if desired by any suitable means for reciprocating eitherthe workpiece of the block.

FIG. 4 illustrates application of the method of the invention totreatment of a workpiece which is of web or band form, running overappropriate guide pulleys and then in friction bearing contact relationwith a block of particulate material as indicated at 62; a spring 64being again employed to maintain the proper pressure bearingrelationship between the workpiece and the block.

FIG. 5 illustrates schematically a device for treating a disc-shapedworkpiece 65 in accord with the method of the present invention; theworkpiece being mounted upon a driving spindle 66 and being subjected toa particulate material supply block 63 backed up by springs 69 for thepurpose of including particulate material in the electroformprogressively as it is plated upon the work piece. It is to beunderstood that in all cases the particulate material supply member mayeither be in friction bearing contact with the electroform beingproduced at a portion thereof which is submerged in the electroplatingsolution, or alternatively the particulate material supply member may bemounted clear of the plating solution while the workpiece is rotated soas to bring portions thereof alternately into the plating solution andthence into friction bearing relation with the material supply block.Thus, it will be appreciated that whereas only a few forms of apparatusfor performing the method of the invention have been schematicallyillustrated and described, the arrangements shown herein are by no meansinclusive of all possible types of apparatuses for the pur pose, andthat various changes may be made therein without departing from thespirit of the invention or the scope of the following claims.

We claim:

1. The method of providing a composite material body comprisingelectroformed material having other discrete material embedded therein,said method comprising subjecting a base member to an electroplatingoperation while disposing in rubbing contact thereagainst a cohesivemass of particulate material, the pressure bearing relationshiptherebetween being such as to cause particles of said particulatematerial to detach from said cohesive mass and to become embedded withinthe electroform as it progresses.

2. The method of providing a composite material body comprising a matrixof electroformed material having other material particles includedtherein, said method comprising conducting a progressive electroplatingoperation while disposing in slide-bearing relation thereagainst acohesive mass of the other material particles, the pressure-bearingrelationship therebetween being such as to cause particles of said othermaterial to detach from said mass and to become embodied within theelectroform so made.

3. The method of providing on a workpiece a composite material bodycomprising a matrix of electroformed material having inclusions of othermaterial particles, said method comprising subjecting the workpiece toan electroplating operation while disposing in friction-bearing relationthereagainst a cohesive mass of the other material particles, thepressure-bearing relationship therebetween being such as to causeparticles of said other material to detach from said agglomeration andto become embedded within the electroplate matrix as it forms.

4. The method of forming a composite material body comprising (a) amatrix of electroformed material having discrete particles of othermaterial included therein, which comprises (b) electrolyticallydepositing the matrix material upon a body, and

(6) simultaneously forcibly interlocking particles of the other materialwith the surface of the matrix by forcing abrading the matrix with acohesive mass of particles of the other material.

(02) and continuing the electrolytical deposition to aflix the particlesto the matrix.

5. The method according to claim 4 wherein (a) the application ofparticles is confined, at any instant, to an area less than the surfacearea of the body,

(b) the particles being progressively applied over the entire surfacearea of the body.

6. The method of forming a'composite material body comprising (a) amatrix of electroformed material having discrete particles of othermaterial included therein, which comprises (b) electrolyticallydepositing the matrix,

(0) simultaneously transferring discrete particles of the other materialfrom a cohesive mass thereof to the matrix, and

(d) continuing the electrolytic deposition of the matrix to afiix theparticles of the other material therein.

References Cited by the Examiner UNITED STATES PATENTS 817,419 4/06Dieffenoach 20436 897,291 9/08 Jullien et a1 20436 898,404 9/08 Edison20436 1,721,949 7/29 Edelman 20415 2,020,117 11/35 Johnston 204-162,061,592 11/36 Rapids 20415 2,086,226 7/37 Hoff 204217 2,278,512 4/42Egli et al 204228 2,360,798 10/44 Seligman et al 204l6 2,391,206 12/45Van der Pyl 204l6 2,424,140 7/47 Beecher 204l6 2,878,171 3/59 Ferrand204l6 JOHN H. MACK, Primary Examiner.

JOHN R. SPECK, JOSEPH REBOLD, Examiners.

1. THE METHOD OF PROVIDING A COMPOSITE MATERIAL BODY COMPRISINGELECTROTORMED MATERAL HAVING OTHER DISCRETE MATERIAL EMBEDDED THEREIN,SAID METHOD COMPRISING SUBJECTING A BASE MEMBER TO AN ELECTROPLATINGWHILE DISPOSING IN RUBBING CONTACT THEREAGAINST A COHESIVE MASS OFPARTICULATE MATERIAL, THE PRESSURE BEARING RELATIONSHIP THEREBETWEENBEING SUCH AS TO CAUSE PARTICLES